Apparatus for mixing liquids



Dec. 23, 1930. uw

APPARATUS FOR MIXING LIQUIDS Filed May 28, 1-929 Patented Dec. 23, '1930UNITED STATES PATENT OFFICE,

. rmnnmcn DUWE, or nmmz-xnsrnn, GERMANY, Ass GNoR 'ro mscnmmnnmnoesnunohwnnnnae A. G., or NUREMBERG, IBAVARIA, GER-MANY, noonrom- 'IION0F GERMANY APPARATUS FOR MIXING LIQUIDS Application filed May as, 1929,Serial No.

My invention relates to apparatus for mixing liquids and more especlallyto apparatus of this kind in which the mixing of a liquid isaccomplished by means of a screw-propeller;

In order to intimately mix liquids of different kinds andproperties,-mixing devices have been used which consist of a containerfor said liquids and a screw propeller drawing-in the liquid nearthebottom of the con tainer and discharging said drawn-in liquid ontothe level of the liquid in the container by means of a discharge memberwhich is of funnel-shaped conformation and of a diameter enlargingupwardly.

An apparatus of this kind, however, is not suitable, if large amounts ofliquid have"to be mixed. In this case the, propeller casing which isopen in the upward direction will become of such greatly enlargedcross-sectionthat the discharge velocity of the liquid will beessentiallydecreased. Also, in large apparatus of this kind it'isdifficult to bring about a proper lateral deflection and uniformdistribution of the liquid when discharging as well as of the jet ofdischarging liquid when coming in contact with the level of the liquidin the container. In addition to this the throw of the dischargingliquid will be of rather small extent.

The general object of this invention consists in providing aconstruction for liquid mixing apparatus operated by screw propellers inwhich apparatus the aforementioned 1 drawbacks are successfully avoided.Essen- "tially, this invention consists in this that the discharge endof the casing of the screw propeller is composed of a plurality ofproperly curved nozzles arranged adjacent to each other and distributedaround the axis of said propeller. According to this invention,furthermore, the radius of curvature. of the upper portion of the wallof said nozzles is smaller than the radius of curvature at the underportion of said nozzles and the end of the said upper portion of thenozzlesis made to project beyond said under portio in order to attain-auniformly distributed j t of discharging liquid in'the form of anumbrellashaped veil of liquid.

366,715, and in Germany, June 13, was.

In amixing apparatus constructed according to my invention, the extentof the throw of the liquid discharging from the propeller casing may beregulated by a regulation of the speed of the" ropeller, for instance,by a regulation of the driving motor. More particularly, in order toattain a proper extent of the throw of liquid discharging from thenozzles, in case of containers having a large diameter, it is ofadvantage to gradually decrease the clear height or vertical diameter ofthe nozzles toward the outside so as to avoid any decrease of velocityof the liquid when dischargin from said nozzles. The accompanyingriawing shows an example of a mixing apparatus constructedaccording tothis invention, Fig. 1 being a ,central cross-section in verticaldirection throughthe novel mixing apparatus, and Fig. 2 a partialhorizontal section through Fig. 1 along the line A-B-thereof. As shownin the drawing, the mixing apparatus comprises a container at and acasing for the screw propeller b. This casing is composed of a pluralityof flanged sectlons and mounted within said container by means of thebearing block d which rests upon the beams 0 and acts as a support forthe driv of the nozzles g is relatively small and the' surface of thedischarge orifice of said nozzles properly inclined towards the levelofthe liquid in the container a, while the radius of curvature of the upver portio'n'z' of the wall of the nozzles is rel tively large. More?over, the upper end of the discharge orifice of the nozzles projectssomewhat beyondthe under end so as toobtain a proper inclination of thesurface of. said discharge orifice. Furthermore, the vertical cleardiameter of the nozzles gradually decreases toward the 106 outside sothat the total cross-section of the liquid discharging from said nozzleswill be equal or approximately equal to the crosssection of the annularchannel is of the propeller casing which contains the propeller blades'b. Because of this construction of the discharge nozzles and thepropeller casing, the liquid will discharge at undiminished speed fromsaid nozzles, which speed may be determined by the s ced of the drivingmotor e for the propeller Also, by reason of the particular shape andinclination of the discharge orifices of the nozzles the liquid will bedischarged therefrom and thrown upon the level of the liquid in thecontainer as a uniform veil of liquid in fan or umbrella-shape. Thedesired width of the throw of the liquid discharging from the propellercasing may now be obtained by a proper adjustment of the speed of themotor e and therewith of the screw propeller b.

I claim:

1. In a mixing apparatus, the combination with a container and ascrew-propeller rotatably disposed therein about a vertical axis, of acasing surrounding said propeller, and a plurality of discharge nozzlesprovided on said casing being arranged in a circle around said casingand curved in a radial plane relative to said container so as todischarge the liquid in fan-shape upon the level of the liquid in saidcontainer.

2. The combination as specified in claim 1, I

in which the discharge orifices of said nozzles are of restrictedcross-section relative to their entrance apertures having across-section substantially equal to the annular cross-section of theportion of said casing surrounding said propeller.

3. The combination as specified in claim 1, in which the clear verticaldiameter of said nozzles gradually decreases toward the outside so thatthe total cross-section of the discharge orifices of said nozzles issubstantially equal to the annular cross-section of the portion of saidcasing surrounding said propeller.

4. The combination as specified .in claim 1, in which the dischargeorifices of said nozzles are of restricted cross-section relative totheir entrance apertures, the total discharge orifice of all saidnozzles having a cross-section substantially equal to the effectiveentrance aperture of the portion of said casing surrounding saidpropeller.

In testimony whereof I affix my signature.

FRIEDRICH DUWE.

